1. Field of the Invention
The invention relates to a device for comminuting feedstock.
2. Description of the Background Art
Devices of this type belong to the field of mechanical process engineering, particularly the conversion of a feed material into an end product of predefined shape and size by way of comminution. Such devices include, inter alia, disc mills, such as those disclosed, for example, by German Utility Pat. No. DE 202 16 056 U1, which corresponds to U.S. Pat. No. 7,134,463. Such disc mills have a rotor, which works together with a stator within a housing. The rotor includes a carrier disc, which is equipped along its outer circumferential area with grinding tools lying within the disc plane. The grinding tools lie opposite to stationary stator tools, arranged at the inner housing wall concentrically around the axis of rotation, at an axial distance with the maintenance of a grinding gap.
Both the rotor and stator tools can be formed by segments and are screwed onto the carrier disc or to the housing wall. This very time-intensive work increases not only the assembly costs during wear-related tool replacement, but also concurrently increases the length of downtimes of the disc mill, which conflicts with efficient utilization. For this reason, rotor and stator tools, which have a complete ring that can be replaced as a whole unit, are already in use in disc mills. This does in fact shorten the tool replacement times, but the profile of the grinding tools is limited in terms of manufacturing technology to a substantially radial fluting.
The conventional art also includes mills, such as those described, for example, in European Pat. Appl. No. EP 2 070 596 A1. The mill disclosed therein has a cone-shaped housing, whose inner circumference is provided with a grinding bed insert, shaped like a hollow truncated cone, to form a stator. Arranged coaxially within the grinding bed insert is a rotor, whose rotor tools are formed by radially oriented impact plates, which are suspended in a pendular manner and with maintenance of the grinding gap strike along the inner circumference of the stator tools. The grinding bed insert, shaped like a hollow truncated cone, forms the stator tools and is inserted as a whole unit into the housing, whereby a clamping ring at the larger-diameter front end of the housing assures the securing against axial positional changes of the grinding bed insert. As in the case of the previously mentioned one-piece tool rings in disc mills, based on the monolithic design of the grinding bed insert here as well only a substantially coaxial fluting on the inner circumference of the grinding bed insert is possible. Variations in the geometry of the fluting, to match the stator tool active surface for comminution to specific feedstock or to achieve a specific processing result, are not possible.